Compressor provided with an oil separator

ABSTRACT

A compressor comprises a compressing device, an outlet chamber, a centrifugal separator for separating lubricating oil from refrigerant gas discharged from the compressing device into the outlet chamber and a casing for accommodating the compressing device, the outlet chamber and the centrifugal separator. A lubricating oil separator assembly comprising a bulkhead forming a refrigerant gas passage and the centrifugal separator assembled with the bulkhead as a unitary body is disposed in the outlet chamber.

BACKGROUND OF THE INVENTION

The present invention relates to a compressor provided with an oil separator.

Japanese Patent Laid-Open Publications No. 11-324910 and No. 2001-289164 disclose compressors comprising a compressing device, an outlet chamber, a centrifugal separator for separating lubricating oil from refrigerant gas discharged from the compressing device into the outlet chamber and a casing for accommodating the compressing device, the outlet chamber and the centrifugal separator.

In the aforementioned compressors, lubricating oil separated from refrigerant gas is led to sliding parts of the compressing device.

Each of the aforementioned compressors has a problem in that the structure of the compressor is complicated and the manufacturing cost of the compressor is high because a separation chamber for accommodating the centrifugal separator is disposed in the casing of the compressor independently of the outlet chamber and a refrigerant gas passage for communicating the outlet chamber with the separation chamber is formed in the casing of the compressor.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a compressor comprising a compressing device, an outlet chamber, a centrifugal separator for separating lubricating oil from refrigerant gas discharged from the compressing device into the outlet chamber and a casing for accommodating the compressing device, the outlet chamber and the centrifugal separator, wherein the structure of the compressor is simpler and the manufacturing cost of the compressor is lower than the compressors disclosed in Japanese Patent Laid-Open Publications No. 11-324910 and No. 2001-289164.

In accordance with the present invention, there is provided a compressor comprising a compressing device, an outlet chamber, a centrifugal separator for separating lubricating oil from refrigerant gas discharged from the compressing device into the outlet chamber and a casing for accommodating the compressing device, the outlet chamber and the centrifugal separator, wherein a lubricating oil separator assembly comprising a bulkhead forming a refrigerant gas passage and the centrifugal separator assembled with the bulkhead as a unitary body is disposed in the outlet chamber.

In the compressor of the present invention, there is no need for disposing a separation chamber in the casing of the compressor independently of the outlet chamber and a refrigerant gas passage for communicating the separation chamber with the outlet chamber in the casing of the compressor because a lubricating oil separator assembly comprising a bulkhead forming a refrigerant gas passage and the centrifugal separator assembled with the bulkhead as a unitary body is disposed in the outlet chamber. Therefore, the compressor in accordance with the present invention is simpler in structure and lower in manufacturing cost than the compressors disclosed in Japanese Patent Laid-Open Publications No. 11-324910 and No. 2001-289164.

In a preferred embodiment of the present invention, the centrifugal separator is formed integrally with the bulkhead.

When the centrifugal separator is formed integrally with the bulkhead, the number of elements becomes smaller and the manufacturing cost becomes lower in comparison with the case when the bulkhead and the centrifugal separator are formed independently of each other and assembled as a unitary body.

In another preferred embodiment of the present invention, the bulkhead cooperates with the surrounding wall of the outlet chamber to form the refrigerant gas passage.

When the bulkhead cooperates with the surrounding wall of the outlet chamber to form the refrigerant gas passage, the weight of the member necessary for forming the refrigerant gas passage decreases to decrease the weight of the compressor.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a sectional view of a variable displacement swash plate compressor for a car air conditioner in accordance with a preferred embodiment of the present invention.

FIG. 2 is a structural view of a lubricating oil separator assembly provided for the variable displacement swash plate compressor for a car air conditioner in accordance with the preferred embodiment of the present invention, wherein (a) is a side view and (b) is a view in the direction of arrows b-b in (a).

FIG. 3 is a fragmentary sectional view of the variable displacement swash plate compressor for a car air conditioner in accordance with the preferred embodiment of the present invention.

FIG. 4 is an exploded perspective view of a cylinder head of the variable displacement swash plate compressor for a car air conditioner in accordance with the preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A variable displacement swash plate compressor for a car air conditioner in accordance with a preferred embodiment of the present invention will be described.

As shown in FIG. 1, a variable displacement swash plate compressor A for a car air conditioner is provided with a rotating shaft 10, a rotor 11 fixed to the rotating shaft 10, a swash plate 12 fitted on the rotating shaft 10 to engage the rotating shaft 10 sidably and to be variable in inclination relative to the rotating shaft 10 and a spring 13 slidably fitted on the rotating shaft 10 to engage the rotor 11 and the swash plate 12. The swash plate 12 is connected to the rotor 11 through a linkage 14 to be variable in inclination relative to the driving shaft 10, thereby rotating synchronously with the rotating shaft 10.

A plurality of pistons 16 engage the swash plate 12 through a plurality of pairs of shoes 15 that slidably engage the outer peripheral portion of the swash plate 12. The pistons 16 are inserted into cylinder bores 17 a formed in a cylinder block 17.

The plurality of pairs of shoes 15, the pistons 16 and the cylinder bores 17 a are distanced from each other in the circumferential direction.

A front housing 19 comprising a cylinder closed at one end cooperates with the cylinder block 17 to form a crank chamber 18 for accommodating the rotating shaft 10, the rotor 11 and the swash plate 12. One end portion of the rotating shaft 10 passes through a boss 19 a of the front housing 19 to extend out of the front housing 19. A seal member 20 is disposed in the annular space between the boss 19 a and the rotating shaft 10.

The rotating shaft 10 is rotatably supported by the front housing 19 and the cylinder block 17 through radial bearings 21 and 22. The rotor 11 is rotatably supported by the front housing 19 through a thrust bearing 23.

Rotating force is transmitted from an external power source, not shown in the drawings, to the one end portion of the rotating shaft 10 through a torque limiter 24 or an electromagnetic clutch, not shown in the drawings, mounted on the boss 19 a of the front housing 19.

A cylinder head 27 comprising a cylinder closed at one end cooperates with a valve plate 28 to form an inlet chamber 25 of annular shape as seen from the side and an outlet chamber 26 of circular shape as seen from the side disposed radially inside the inlet chamber 25.

The valve plate 28 is disposed between the cylinder block 17 and the cylinder head 27. The valve plate 28 is provided with inlet holes 28 a and outlet holes 28 b. Inlet valves 29 for opening and closing the inlet holes 28 a and outlet valves 30 for opening and closing the outlet holes 28 b are fitted to the valve plate 28.

The inlet chamber 25 communicates with an inlet port 31 a formed in the surrounding wall of the cylinder head 27 and communicates with the cylinder bores 17 a through the inlet holes 28 a and the inlet valves 29.

The outlet chamber 26 communicates with an outlet port 31 b formed in the surrounding wall of the cylinder head 27 and communicates with the cylinder bores 17 a through the outlet valves 30 and the outlet holes 28 b.

The rotating shaft 10, the rotor 11, the swash plate 12, the shoes 15, the pistons 16, the cylinder bores 17 a, the valve plate 28, the inlet valves 29, the outlet valves 30 and so forth cooperate to form a compressing device.

A lubricating oil separator assembly 32 is disposed in the outlet chamber 26. As shown in FIGS. 1 to 4, the lubricating oil separator assembly 32 comprises a bulkhead 32 a forming a refrigerant gas passage 33. The bulkhead 32 a has a short cylindrical shape closed at one end. The lubricating oil separator assembly 32 further comprises a centrifugal separator 32 b of double cylindrical shape. The centrifugal separator 32 b is formed integrally with the bulkhead 32 a. The bulkhead 32 a is press fitted in, or fitted in and fixed to, the outlet chamber 26 with its open end directed toward the valve plate 28 and its circumferential wall pressed against or slidably abutted on the circumferential wall of the outlet chamber 26. The bulkhead 32 a cooperates with the valve plate 28 to form a refrigerant gas passage 33. The refrigerant gas passage 33 communicates with an annular space 32 d formed between the outer cylinder and the inner cylinder of the centrifugal separator 32 b through holes 32 c penetrating the bottom plate of the bulkhead 32 a and the outer cylinder of the centrifugal separator 32 b. The holes 32 c are directed tangentially relative to the annular space 32 d. The inner cylinder of the centrifugal separator 32 b communicates with a portion of the outlet chamber 26 outside the refrigerant gas passage 33 and the outlet port 31 b.

A displacement control valve 34 is disposed in the cylinder head 27. The displacement control valve 34 is disposed midway of a communicating passage 35 extending between the lower part of the portion of the outlet chamber 26 outside the refrigerant gas passage 33 and the crank chamber 18. The crank chamber 18 communicates with the inlet chamber 25 through an orifice passage not shown in the drawings.

Projections 27 a extending from the bottom plate of the cylinder head 27 pass through holes 32 a′ formed in the bottom plate of the bulkhead 32 a to extend into the refrigerant gas passage 33. The projections 27 a abut the valve plate 28 to force it against the cylinder block 17. A part of the communicating passage 35 is formed in one of the projections 27 a.

The front housing 19, the cylinder block 17, the valve plate 28 and the cylinder head 27 are assembled as a unitary body by through bolts 36.

The operation of the variable displacement swash plate compressor A will be described.

In the variable displacement swash plate compressor A, the driving force of the external power source, not shown in the drawings, is transmitted to the rotating shaft 10 through the torque limiter 24 to rotate the rotating shaft 10. The rotation of the rotating shaft 10 is transmitted to the swash plate 12 through the rotor 11 and the linkage 14. The rotation of the swash plate 12 causes reciprocal movement of the outer peripheral portion of the swash plate 12 parallel to the rotating shaft 10. The reciprocal movement of the outer peripheral portion of the swash plate 12 is transmitted to the pistons 16 through the shoes 15. Thus, the pistons 16 reciprocally move in the cylinder bores 17 a. Refrigerant gas returns from an external refrigeration circuit to be sucked into the cylinder bores 17 a through the inlet port 31 a, the inlet chamber 25, the inlet holes 28 a and the inlet valves 29. The refrigerant gas is compressed in the cylinder bores 17 a to be discharged through the outlet holes 28 b and the outlet valves 30 into the refrigerant gas passage 33 which is a portion of the outlet chamber 26 surrounded by the bulkhead 32 a and the valve plate 28. The refrigerant gas flows in the refrigerant gas passage 33 toward the holes 32 c to pass through the holes 32 c, thereby entering into the annular space 32 d. The refrigerant gas whirls in the annular space 32 d to flow into the portion of the outlet chamber 26 outside of the refrigerant gas passage 33. The refrigerant gas flows out of the compressor into the external refrigeration circuit through the inner cylinder of the centrifugal separator 32 b and the outlet port 31 b.

The displacement control valve 34 controls opening and closing of the communication passage 35 depending on refrigerant gas pressure in the inlet chamber 25, or differential pressure between refrigerant gas pressure in the outlet chamber 26 and refrigerant gas pressure in the inlet chamber 25 to control the introduction of the refrigerant gas in the outlet chamber 26 into the crank chamber 18, thereby controlling internal pressure in the crank chamber 18 and displacement of the compressor A. As a result, the refrigerant gas pressure in the inlet chamber 25 or the differential pressure between the refrigerant gas pressure in the outlet chamber 26 and the refrigerant gas pressure in the inlet chamber 25 is controlled at a desired level.

When the refrigerant gas whirls in the annular space 32 d in the centrifugal separator 32 b, centrifugal force is applied to lubricating oil mist to make it adhere to the outer circumferential wall of the annular space 32 d, thereby separating the lubricating oil mist from the refrigerant gas.

The lubricating oil mist adhered to the outer circumferential wall of the annular space 32 d flocculates to flow down along the outer circumferential wall of the annular space 32 d, thereby dropping down from the lower end of the outer circumferential wall of the annular space 32 d. Thus, lubricating oil accumulates in the bottom part of the portion of the outlet chamber 26 outside the refrigerant passage 33.

The lubricating oil accumulating in the bottom part of the portion of the outlet chamber 26 outside the refrigerant passage 33 is led into the crank chamber 18 entrained by the refrigerant gas in the outlet chamber 26 through the communication passage 35 and the displacement control valve 34 to accumulate in the bottom part of the crank chamber 18. The lubricating oil accumulating in the bottom part of the crank chamber 18 is drawn up by the rotating swash plate 12 to lubricate sliding parts of the compressing device disposed in the crank chamber 18.

In the compressor A, the lubricating oil separator assembly 32 comprising the bulkhead 32 a forming refrigerant gas passage 33 and the centrifugal separator 32 b assembled with the bulkhead 32 a as a unitary body, more concretely, formed integrally with the bulkhead 32 a, is disposed in the outlet chamber 26 to separate lubricating oil from the refrigerant gas. Therefore, there is no need for disposing a separation chamber in the casing of the compressor A independently of the outlet chamber 26 and a refrigerant gas passage for communicating the separation chamber with the outlet chamber 26 in the casing of the compressor A. Therefore, the compressor A is simpler in structure and lower in manufacturing cost than the compressors disclosed in Japanese Patent Laid-Open Publications No. 11-324910 and No. 2001-289164.

The centrifugal separator 32 b is formed integrally with the bulkhead 32 a forming the refrigerant gas passage 33. Therefore, the number of elements becomes smaller and the manufacturing cost becomes lower in comparison with the case when the bulkhead 32 a and the centrifugal separator 32 b are formed independently of each other and assembled as a unitary body.

The valve plate 28 forming a part of the surrounding wall of the outlet chamber 26 forms a part of the surrounding wall of the refrigerant gas passage 33. Therefore, the weight of the member necessary for forming the refrigerant gas passage 33, more concretely the weight of the bulkhead 32 a, decreases to decrease the weight of the compressor A.

The bulkhead 32 a and the centrifugal separator 32 b can be formed independently of each other and assembled as a unitary body.

The present invention can be used for various kinds of compressors for compressing gas into which lubricating oil mist disperses.

While the present invention has been described with reference to preferred embodiments, one of ordinary skill in the art will recognize that modifications and improvements may be made while remaining within the spirit and scope of the present invention. The scope of the invention is determined solely by the attached claims. 

1. A compressor comprising a compressing device, an outlet chamber, a centrifugal separator for separating lubricating oil from refrigerant gas discharged from the compressing device into the outlet chamber and a casing for accommodating the compressing device, the outlet chamber and the centrifugal separator, wherein a lubricating oil separator assembly comprising a bulkhead forming a refrigerant gas passage and the centrifugal separator assembled with the bulkhead as a unitary body is disposed in the outlet chamber.
 2. A compressor of claim 1, wherein the centrifugal separator is formed integrally with the bulkhead.
 3. A compressor of claim 1, wherein the bulkhead cooperates with the surrounding wall of the outlet chamber to form the refrigerant gas passage. 